Health officials in Nigeria are gearing up for a massive emergency polio immunization drive after two children were paralyzed by the disease.
The two new polio cases in Nigeria are the first detected on the African continent in more than two years.
Nigerian health officials plan to vaccinate nearly 5 million kids across the northeast of the country in an effort to contain this latest outbreak.
The re-emergence of polio in Nigeria is a major setback for global efforts to eradicate the disease.
Prior to this week, the polio virus appeared to be on the verge of defeat: Afghanistan and Pakistan were the only countries reporting ongoing transmission of the virus. Including these two children who've been paralyzed in Nigeria, there've been only 21 polio cases reported anywhere in the world this year.
The two Nigerian cases were found in the volatile northeastern state of Borno along the border with Chad. The area is a stronghold of Boko Haram, which has made routine immunization drives difficult. The terror group has publicly denounced the vaccination campaigns as a Western plot, killed immunizers and made it difficult for government health officials to even enter some parts of the country.
Nigeria's health minister, Isaac Adewole, issued a statement saying that the cases were only detected because of a military offensive against the militant Islamist group.
"The discovery and confirmation of the outbreak was as a result of strengthened surveillance due to improved accessibility which has been made possible by the recent military action in liberating more communities in the North-Eastern part of the country," according to the statement.
Adewole added, "Our overriding priority right now is to rapidly boost immunity in the affected areas to ensure that no more children are affected by this terrible disease."
The World Health Organization has also vowed to pour resources into Nigeria to try to make sure the virus is contained in the Nigeria/Chad border region and doesn't regain a foothold in Africa.
Nigeria has been the Achilles' heel of polio eradication in Africa in the past.
A decade and a half ago, religious leaders in some parts of Nigeria actively denounced polio vaccination as part of a Western plot to sterilize Muslim children.
Even as other nations on the continent wiped out polio, Nigeria served as reservoir where the virus survived, sparking outbreaks throughout West Africa as travelers moved throughout the region.
Just four years ago, Nigeria accounted for more than half of all the polio cases reported worldwide — 122 of the 223 global cases in 2012. Up until this week it appeared that Nigeria had successfully eliminated polio and was on track to be declared polio-free by the WHO next summer. It takes three years without a case to be eligible for the designation.
UNICEF, which has been one of the lead agencies fighting polio in Nigeria, vowed to redouble efforts in the region and "not stop until we reach every child with polio vaccination."